Traditional plunge dipping — immersion of sheep in organophosphate or pyrethroid insecticide baths — was historically mandatory in many countries for ectoparasite control (sheep scab, blowfly, lice). Welfare concerns include submersion stress, inhalation of dip fluid, chemical toxicity, and cold exposure. Compulsory dipping was abolished in the UK in 1992 following human health concerns over organophosphate exposure. Alternative ectoparasite control methods include pour-on products, injectable antiparasitics (ivermectin), and spot treatments. Biosecurity-based approaches — flock testing, movement controls, and targeted treatment — reduce reliance on prophylactic dipping. Where dipping remains practised, welfare standards address dip concentration, bath temperature, swim time, and recovery pen design. Welfare-positive outcomes require trained operators, appropriate facilities, and product rotation to prevent resistance.